The aim was to isolate and characterize Riemerella anatipestifer organisms from disease outbreaks in ducks in Kerala.Materials and Methods: Ducklings, suspected of Riemerella infection, were sacrificed and subjected to post-mortem examination. Heart blood smears and impression smears from liver and spleen were examined for the presence of pathogenic organisms. Heart blood, lung, liver, and spleen collected aseptically from the birds were subjected to isolation trials in brain heart infusion agar and 10% bovine blood agar. The isolates were characterized based on morphology, cultural characteristics and biochemical tests, and their identity were confirmed by polymerase chain reaction (PCR) and the PCR amplified DNA was sequenced. The antibiotic sensitivity testing of the isolates were carried out using six antibiotics viz ciprofloxacin, chloramphenicol, enrofloxacin, amoxycillin, cotrimoxazole, and gentamicin.Results: Colonies suggestive of Riemerella organisms could be isolated on blood agar. Biochemical characterization and PCR confirmed the identity of isolates as R. anatipestifer. The nucleotide sequence of the PCR product showed 99% homology to the R. anatipestifer sequences in the NCBI. The antibiogram revealed that the organisms were sensitive to ciprofloxacin, enrofloxacin, and gentamicin. Conclusion:The present study suggests that the PCR assay can facilitate fast and proper identification of R. anatipestifer infection in ducks. The assay can also differentiate between R. anatipestifer and Pasteurella multocida and can replace the traditional methods of differentiation which are cumbersome and time-consuming.

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Porcine reproductive and respiratory syndrome (PRRS) caused by an arterivirus is characterised by reproductive disorders in sows, and post-weaning pneumonia and growth reduction in piglets. Though the virus has been detected in Kerala, no systematic study has been carried out to ascertain its genotype and molecular epidemiology. In the present study, 7 PRRS virus (PRRSV) positive samples collected from incidences of PRRS in Kerala during 2017-2019 were subjected to ORF5, ORF7 and Nsp2 gene based reverse transcription polymerase chain reaction and the specific amplicons generated were sequenced. On BLAST analysis it was revealed that all the sequences were of genotype 2 (North American genotype). Phylogenetic analysis of ORF5 sequences, grouped them under subgenotype 4 with close clustering with other isolates from Kerala, Mizoram and Assam. Nsp2 gene sequence based phylogenetic analysis grouped the isolates under subgenotype 3 with similarities to isolates from Mizoram. Phylogenetic analysis based on ORF7, clustered the isolates under study with PRRSV isolates from Mizoram and Meghalaya. In Nsp2 sequences, a 30 amino acid discontinuous deletion was observed. On analysis of amino acid sequences of ORF5 of Kerala isolates and those from India, it was seen that the Kerala isolates showed closer similarity to PRRSV isolates from Assam than to the other Indian isolates. The study reveals that PRRSV strains prevalent in Kerala share close relationship with other PRRSV isolates in India. This may be due to spread of the virus from these regions to Kerala due to animal movement. Concerted efforts should be undertaken to check unauthorized animal movement to control spread of this economically important disease.

Feline panleukopenia (FPL) is an acute viral infection of domestic and wild felids causing high mortality among non immune kittens. Commercially available immunochromatographic (IC) strips, haemagglutination (HA) test and polymerase chain reaction (PCR) were employed to detect FPLV. In the current study IC strip test and HA test were compared with PCR. A total of 27 faecal samples from cats clinically suspected for FPL infection were collected from five districts of Kerala, India. Out of 27 samples tested, 10 were positive by IC strips, while 8 and 21 samples were found positive by HA test and PCR, respectively. On statistical analysis, specificity of IC strip and HA test versus PCR was excellent (100 per cent), whereas sensitivity was poor. In comparison with PCR, sensitivity for IC strip test and HA test was 47.6 per cent and 38.1 per cent, respectively. The study showed PCR assay as a sensitive, specific and rapid technique for FPLV detection in cats using faecal specimens.

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The present study was undertaken to assess the seroprevalence of Bovine Herpes Virus 1 (BoHV 1) in cattle in and around Thrissur district employing ELISA and to detect the presence of the virus from suspected cases of abortion in cattle using PCR assay. A total of 182 serum samples were screened using commercially available ELISA kit of which 22 were found positive for BoHV1 antibody with a seropositivity of 12.09 per cent. For the detection of BoHV1 virus in aborted cases, a PCR assay was standardised targeting glycoprotein C gene of BoHV1. Out of a total of 13 aborted foetal tissue samples, six were found to be positive with an amplicon size of 179 bp. Further, the amplicons were confirmed by nucleotide sequencing. Phylogenetic analysis of the sequences showed that our sample from Kerala grouped with isolates from India (Gujarat and UP), Brazil, Switzerland, and USA.

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Haemonchus contortus commonly called the stomach worm or wire worm of ruminants inhabits the abomasum and is considered to be one of the economically important gastrointestinal strongyles in goats. In the present study, H. contortus was identified by PCR using the primers targeting partial 5.8S and partial internal transcribed spacer region 2 (ITS-2). Adult worms were identified morphologically and genomic DNA was extracted using DNeasy Blood and Tissue kit (QIAGEN, Germany). Gradient PCR protocol was standardised using the extracted genomic DNA. Ten-fold serial dilution of adult DNA was used to analyse the minimum detection limit and the products were amplified upto the tenth dilution. Cross reaction of primer sets was checked using the DNA extracted from predominant adult srongyles like Oesophagostomum columbianum and Trichostrongylus colubriformis and no cross reaction was seen at the optimum annealing temperature (60.7°C).